Multiple-unit tube



Jan. 5, 1932. s. LOEWE MULTIPLE UNIT TUBE Filed Jan. 19, 1927 2 Sheets-Sheet l INVENTOR SEGMUND LOEWE 5% g a & 61 W ORNEY Jan. 5, 1932.

s. LOEWE MULTIPLE UNIT TUBE Filed Jan. 19, 192 2 Sheets-Sheet 2 INVENTOR SXEGMUND LOEWE BY /l/4 ORNEY Patented Jan. 5, 1932 I D -1 F I 1 srnsivioun nonwnor BERLIN, rnmnmnmjemmsnmnssienon 'ro RADIO comm tc anon or AMERIGA,;AeonPoRATIoNOFDELAWAR 7 MULTIPLE-UNIT, 'rUBi Application iiled January 19,1927; Serial No. 161,999, and in Germany M rch s, 192a.

' This invention relates to multiple-unit tubes. 5 Multiple or multiple-unit tubes are cascade amplifier systems in which a plurality of individual or unit systems comprising a cathode. one or several grids,and an anode or plate (hereinafter briefly called gridanodesystems) with a corresponding number of coupling elements usually consisting of a plate resistance,'a transfer condenser, and a leak resistance, are assembled Within a single vacuous space so as to constitute a single tube. Tribes of this kind serve foraperiodic high frequency amplification as well as for low' frequency (resistance coupied) amplification and for rectification.

The manufacture of such multiple-unit systems, especially the large-scale manufacture thereof, is attended with considerable difiiculty, which, however, can be obviated by the manufacturing* method disclosed in the present invention. The manufacturing method consists in the division of the con struction of the entire system into a number of individual elements which are separately assembled so thatthe work of mounting the system resolves itself into the mere work of connecting the individual elements so prepared. More particularly'sipeaking, the assembly of the system from prepared individual elements can be accomplished by means of a permanent reproduction or pattern (accurate as to form or shape) of the glass mount which is to carry the system in the actual tube. After the assembly of the entire tube system has been completed, the same is removed from the model or pattern and is fitted upon the actual glass stem or mount. What remains to be done to complete the structure is to establish a few connections, namely, the union with the leading-inv wires sealed into the press of the air stem or mount. The system thus mounted will then be ready for sealing. into the bulb. Among other things, this process results in a considerable saving in manufacturing cost. The method will be further explained in what follows by the aid of a composite multiple-unit tube comprising three separate systems with their coupling elements.

In the accompanying drawings Figure 1 is first mounted;

. Figure'5 is an elevation of the stem and mount, partly in section;

Figure 6 is anelevation 'of the mount with thevarious units mounted thereon and Figure 7 is a viewinperspective of a modified form-of a'coupling unit.

Figure 1 shows by wayof example the key diagram of a three stage amplifier assembled in a single tube; Referring totliat figure,--the' I single glass envelope for the tube is indicated diagrammatically at 100, and 1, 2, 3, indicatethe first, second and third grid-plate system. 4,5, 6, is the first, and-7,"8, 9, the second cou? pling element. The filaments of the first two systems are connected in series, whereas the filament of the third system is connected in parallel to the two former filaments. The required terminals ofthe tubeare marked by circles. Hence, the tube is provided with six terminals, to be more precise, one for the first grid, two for the connections withtheheating circuitcfor the-cathodes,'another one for the first two plate circuits, one for, the last grid, and for the last plate. r

According to the invention, the assembly is effected so that (as indicated by the dotted t Figure 3 shows by way of example in what Way the coupling. elements may becombined loo so as to constitute a single constructional unit. On the left-hand side is a plate resistance 11, on the right a grid leak (resistance) 12, in the middle a coupling condenser 13. The mechanical union of these constituent parts to form a single constructional unit is effected by giving sufiicient mechanical rigidity to the condenser 13, which consists of two strips of copper wound about each other with the interposition of mica laminae, so that it can serve at the same time as a support for high-ohmic resistances.

The strength attained by such a construction may be enhanced by fastening a connector piece 26, of glass, as shown in Figure 7, to condenser 13 and to which the resietmce lead wires are attached.

In order to realize an arrangement as illustrated in Figure 1 three elements as depicted in Figure 2 and two elements according to Figure 3 must be assembled together. This assembly is not effected direetly upon the mount which is called upon to carr, the entire three-unit system in the finishe tube, but rather upon a metallic pattern 14, (see Fig. 4). In this manner all danger of breakage is practically preeluded during the work of assembly. Another advantage is that this makes for greater uniformity in assembly and greater regularity, as a consequence, in operation and efficiency.

, Figure 4 is a perspective view of the prefarable metallic reproduction of the mount by the aid of which the assembly of the system can be effected. This metal replica of the mount consits of a base plate 14 which has a pair of metal fingers 15 upon which the arts of the system are placed side by side.

or instance, the supporting wires 16, 17, of the coupling element, Figure 3, are bent around the fingers to form eyelets or books which engage the side rods 15 of the mount. The grid-plate system is mounted in a similar manner, and the same is then first united separatel with the coupling element previously tted'on, for instance, by making a welded joint at 18. In a similar manner, upon the auxiliary device illustrated in Figure 4, there is mounted the second coupling element, the second grid-plate system, and finally the third grid-plate system, being united with the system parts previously fitted on by welding or by clamping action. The system after having been completely mounted, is 'then taken off from the reproduction or pattern or former of the mount shown in Figure 4 and is shifted to and mounted upon the actual mount shown in Figure 5.

Figure 6 shows an arrangement of the systerns upon'the stem or mount 50. The latter contains the six seals or leading-in wires 19 with which connection to the systems is therem established by welding or clamping.

i entire mounting work may'thus be completed. This scheme offers the further advantage that the individual systems, especially the coupling elements, can be previously tested as to their electrical function before they are combined and united with the other parts of the system. The system fitted upon the glass stem and connected with the leadin -in wires is thereupon sealed in a glass bulb in the well known manner and evacuated. By means of this process it is possible to build very complicated structures in a uniform and cheap manner with noticeable freedom'from scrap and waste.

Figure 3 further shows that the wires 16, 17 were chosen of larger cross-section than the other wires. This is done for reasons of strength, because the said wires, as will be seen from Figure 4, are bent over to form eyelets and because they have to fulfill at the same time the requirement of increasing the mechanical strength. For the same reason, the wire 20 is chosen of a larger cross-section, on the ground that, apart from serving as an electrical supply lead it has this further purpose of afiording mechanical union or strength for the entire assembly.

Having thus described my invention, what I claim is:

A multiple unit tube comprising a base, two parallel members extending therefrom, and a plurality of amplified units and co in units mounted on said members, each 0 sai amplifier units comprising a cylindrical plate, a filament at the axis thereof, a d between the filament and plate and 4: r0 of insulating material for holding the leads to the grid, plate and filament in spaced relation, each of said coupling units comprisin a condenser and a pair of resistances, and leads to the condenser supporting said resistances and engaging said parallel members for supporting the coupling unit comprisin the condenser and resistances, on said paral el members.

SIEGMUND LOEWE. 

